1. Technical Field
The present invention relates to an image processing apparatus, an image processing method, an image capturing apparatus, an image capturing method, and a computer readable medium.
2. Related Art
A technique for using a phase plate having a 3-dimensional curved surface to hold an optical transfer function of an optical system substantially constant within a range set by a focal position is known, as in, for example, Japanese Patent Application Publication No. 2006-94469 and Japanese Unexamined Patent Application Publication No. 11-500235.
With this technique, however, it is necessary to provide a separate distance measuring device to measure the subject distance with an external active device. Even when the subject distance is unknown, appropriate restoration of the subject image is desired.